depends. webcams you need a computer to watch. digitalww's $50 rear view camera you just need an RCA input monitor. this means that if you have a LCD for your computer, you don't need to open a program to look back.

What i was thinking about doing was puting 3 inch armor all over my car, and using cameras and visual overlays where the windows would have been. Oh, and a laser that i can target with a touchscreen. Yeah, sounds like a good idea?